Precision machine tool stop

ABSTRACT

A precision machine tool stop mechanism to control the amount of movement of a machine tool. The mechanism comprises a main shaft member with individual engagement increments formed thereon at predetermined intervals, a detachable housing body movable longitudinally along the shaft, controllable pawl members within the housing adapted to engage and disengage the shaft member at select increments, a pawl actuating collar extending to the pawl members within the housing and adapted to control actuation of the pawl members in and out of engagement with the shaft member such that when in engagement the pawls and shaft member are locked to form a unitary structure and when out of engagement the housing is allowed to move freely along the main shaft to any select increment position. A fine adjustment sleeve may be carried by the housing and movable in fine increments in a direction parallel to the axis of the main shaft member.

United States Patent Primary Examiner-Gil Weidenfeld Attomey-Jack M.Wiseman Stites 1 Sept. 5, 1972 [54] PRECISION MACHINE TOOL STOP [57]ABSTRACT Inventor! William fi 4201 Fail Oaks, A precision machine toolstop mechanism to control M61110 parkicallf- 4 2 the amount of movementof a machine tool. The

22 F1 d: N mechanism comprises a main shaft member with in- 1 W dividualengagement increments formed thereon at PP 92,599 predeterminedintervals, a detachable housing body movable longitudinally along theshaft, controllable 52 US. members within the musing adapted engage EInt. n and disengage the shaft member at select increments,

[58'] Field 0 Search 90/1 1 a pawl actuating collar extending to thepawl members 5 7 83/529 within the housing and adapted to controlactuation of v the pawl members in and out of engagement with the Y "messhaft member such that when in engagement the pawls [56] Rafe Cited andshaft member are locked to form a unitary struc- UNITED STATES PATENTSwhen f g g g e u s is ow to move eey ong e mam s to any select incrementposition. A fine adjustment sleeve may be carried by the housing andmovable in fine increments in a direction parallel to the axis of themain shaft member.

12 Claims, 9 Drawing Figures PATENIEDSEP SIQTZ 3 8 937 SHEET 1 [IF 2INVENTOR. 3 WILLIAM 5. sn 15s 9 '0 BY MW 477 DRIVE Y PRECISION MACHINETOOL STOP BACKGROUND OF THE INVENTION tionship to a work piece.

There are presently available various stops for controlling the movementof machine tools as it operates on a work piece. For example, on avertical milling machine it has been common to utilize a screw and nutcombination to set the stops for controlling the vertical distance ofGavel of the spindle carrying the cutters. In setting up the machine,two threaded nuts, one being a lock nut, may be positioned along thescrew for setting the extremity of movement. The nuts are screwed up anddown the shaft to the desired stop position. This is time consuming andlaborious.

SUMMARY OF THE INVENTION The present invention teaches a precisionmachine tool stop which may be precisely set to any of various positionsas desired. The stop may be set to the precise position very rapidly andwith little physical effort.

An exemplary embodiment includes a main shaft member carrying individualprojections along the longitudinal axis in the form of milled ratchetteeth. A housing assembly in the form of a slide block surrounds theshaft and houses precision pawl members adapted to engage the ratchetteeth of the shaft member. The pawl members are movable laterallytowards and away from the shaft. The pawl members engagement anddisengagement with the ratchet teeth are controlled by an actuatingmeans including a quick release lever. The actuating means engages thepawl members to control movement of the pawl members towards and awayfrom the shaft. When the pawls engage the shaft they are locked in placesecuring the housing body to the shaft. When the pawl members are awayfrom the shaft, the housing body is disengaged from the shaft and freeto move along the longitudinal axis of the shaft. A vernier sleeve iscarried by the housing to be adjustable in a direction parallel to theaxis of the shaft. Coarse adjustment of the stop position may berealized through select positional engagement of the shaft and pawl.Fine adjustment may then be set by the vernier sleeve.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view of aprecision machine tool stop according to the present invention;

FIG. 2 is a horizontal cross-sectional view of the main shalt of thetool stop taken along the line 2-2 of FIG. 8 is an enlarged fragmentaryelevational view of the slide block of the stop shown in FIG. 3; and

FIG. 9 is an enlarged fragmentary sectional view illustrating a pawl ofthe stop in engagement with the shaft of the tool stop.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 illustrates inperspective a precision micrometer machine tool stop according'to theteachings of the present invention and referred to by the generalreference character 1. The tool stop 1 includes a main shaft 3 carryingat opposing ends means for securing with a machine tool to which thestop is to be utilized. For example, the depicted structure of FIG. 1has been adopted to be incorporated on a vertical milling machine. Atone end, the shaft 1 carries a rectangular type slot 5 which may engagea vice carried by the table of the machine tool and at the other end anaperture 7 to engage a fastener securing the shaft 3 to a support on themachine.

The shaft 3 is milled finite steps so as to form a plurality of evenlyspaced projections in the form of ratchet stop teeth 9 along thelongitudinal axis. The depicted shaft 3, as further illustrated by thecross-sectional view of FIG. 2, carries four sets of teeth 9 spacedapart about its outer periphery. Obviously, the shape and number of setsof teeth 9 can vary. As shown, the teeth 9 are spaced apart along thelongitudinal axis in equal increments, for example, 0.100 inches.Preferably, the shaft 3 is machined with precision to form the teeth 9so as to allow precise settings. Intermediate adjacent sets of teeth isformed an L- shaped guide track 10 extending along the longitudinalaxis. The tracks 10may each carry a scale designating relative positionsalong the shaft.

Movable along the longitudinal axis of the shaft is a stop (FIG. 3)referred to by the general reference character 12. The stop 12 includesa spindle stop slide block 13 further depicted in detail in FIGS. 3, 4and 8. The slide block 13 has an internal main aperture 15 of aconfiguration conforming with the external periphery of the shaft 3about the teeth 9. For example, the aperture 15, when viewed inquadrants, includes four stairstep configurations joined together tocoincide with the outer periphery configuration of the milled shaft 3 asshown in FIG. 2. Thus, the aperture forms a set of four L-shaped grooves16 to accommodate the tracks 10 of the shaft 3. Hence, the block 13 hasfree axial movement relative to the shaft 3, but not free stoprotational movement relative to the shaft 3. Spaced apart about thespindle block are two radially disposed rectangular type slots 17opening to both the outer wall of the block 13 and the central aperture15. Axially of the block and extending through it are apertures 19. Itmay also be noted that at its upper end, the block 13 carries aplurality of line threads 20.

Intermediate the end surfaces of the block 13 is a circular guide groove21 which extends about the entire circumference of the block. Receivedby the groove 21 is an actuating collar 36 further depicted inperspective in FIGS. 3-7. The actuating collar 36 is in the form of acylindrical wall with an actuating arm 25 extending therefrom. Tofacilitate movement of the collar 36, a handle 28 adapted to be graspedby a finger or hand is connected to the actuating arm 25. The axialopening 36' of the collar 36 is sufficient to permit free movementthereof in the axial and rotatable direction relative to the shaft 3.

Within each slot 17 of a diametrically opposite pair of slots 17 is asubstantially rectangular pawl 29 (See FIGS. 3, 4, 6 and 9) having nearone end an aperture 31 for receiving a pin 33, which pin 33 extendsdownwardly therefrom. The pawls 29 are each free to slide within theirassociated slot 17. The direction of displacement is radial to thelongitudinal axis of the shaft 3. The pawls 29 each carry a ratchet stopjaw 35 shaped and spaced apart to complement interlocking relationshipwith the ratchet stop teeth 9 on the shaft 3.

Disposed within the actuating collar 36 is a cam ring 23, which ispressed fitted within the actuating collar 36 for movement therewith.Formed in the cam ring 23 is a suitable axial opening to permit freemovement thereof in the axial and rotatable directions relative to theshaft 3. Also formed in the cam ring 23 are a plurality of cam slots 27,which are diametrically opposite from one another and are eccentricallydisposed relativeto the axis of the shaft 3. Received respectively bythe cam slots 27 are the pins 33 of the pawls 29.

Also disposed within the actuating collar 36 between the cam ring 23 andthe block 13 is a retainer ring 23' (FIGS. 3-7). The retainer ring 23'is formed with a central opening 23" that is similar in configuration tothe aperture 15 of the block 13. Thus, the retaining ring 23 has freeaxial movement relative to the shaft 13 but not free rotational movementrelative to the shaft 3. The retaining ring 23' is slip fitted in theactuating collar 36 'so as to support the same for rotation. Thus, theretaining ring 23' supports the actuating collar 36 while permitting theactuating collar to rotate relative thereto and also relative to theshaft 3. The retainer ring 23' moves inthe axial direction with theactuating ring 36.

Formed in the retainer ring 23' are slots 50 which are suflicient insize to receive the pawl pins 33 without interfering with the movementthereof within the eccentric slots 27 of the cam ring 23. In additionthereto, formed in the retainer ring 23' are suitable openings 51, whichare in'reg'ister with the openings 19 of the block 13. Suitable screws34 are received through aligned openings 19 and 51 to secure theretainer ring '23 to the block 13. Thus, the retainer ring. 23 issupported by the block 13 through the screws 34. The block 13 can movein an axial direction but not in a rotatable direction. The actuatingcollar 36 is supported by the retainer ring 23. The actuating collar 36is free to rotate about the shaft 3 relative to the retainer ring 23'and relative to the block l3. The actuating collar 36 moves in unison inthe axial direction relative to the shaft 3 with the block 13 and theretainer ring 23'. The cam ring 23 moves in unison with the actuatingcollar 36 both in the rotational direction and in the axial direction'asan integral part thereof. Therefore, rotation of the actuating collar 36imparts rotation to the cam ring 23 relative to the block 13, relativeto the retainer ring 23 and relative to the shaft 3.

Further viewing the cam ring 23 of FIG. 6, it will be noted that as aresult of the angle of the eccentric cut slots 27 that the pin 33 withineach of the slots 27 is displaced radially relative to the axis of theshaft 3 by the engaging wall surrounding the associated slot 27, inresponse to the rotation of the cam ring 23 about the axis of the shaft3. Asthe cam ring 23 is rotated, the

pins 33 are displaced within the slots to urge the associated pawls 29into and out of engagement with'the teeth 9 of the shaft 3. Thus,rotational movement of the cam ring 23 results in radial displacement ofthe pawls 29. Rotating the cam ring 23 in a clockwise direction asdesignated in FIG. 1 causes radially inward displacement of the pawls29, i.e., the pawls 29 move toward the aperture 15 and the shaft 3,since the pins 33 are moving along the eccentric cut slots 27. Thus, theshaft 3 and the housing 12 are locked as a unitary structure. Rotationof the cam in a counterclockwise direction results in a retraction ofthe pawls and release of engagement of the stop 12 with the shaft 3. Thecam ring 23 through the pins 33 urge the pawls 29 away from the centerof the shaft. When the pawls 29 are out of engagement with theindividual teeth 9 on the shaft 3, the stop 12 is free to slide alongthe shaft 3 in the longitudinal direction by relationship of the tracks10 and grooves formed in the stop 12.

The top edge of the collar 36 engages a vernier adjustrnent thimble 41having an aperture 43 through thimble carries internal threads 45designed to be compatible with the threads 20 on the block 13. Thethimble threads 45 engage the threads 20 such that the thimble 41 ismovable up and down relative to the longitudinal axis of the shaft 3.The thimble 41 includes a flat top surface 47 along the upper edge ofthe side sur face which serves as the stop surface for the mechanism 1.The thimble 41 is knurled along an external surface to provide africtional engagement with the fingers of an operator for easieradjustment of the sleeve position. It may be noted that the threads 20and 45 are finally graduated, e.g., in the order of 40 threads per inch.Thus, the position of the vernier thimble 41 may be changed minuteamounts along and parallel with the axis of the shaft 3. The outer edgeof the thimble sleeve 41 carries a scale 49 (FIG. 1) to allow formeasured adjustments. The scale 49 may be marked off such that for eachdegree of rotation of the thimble in relationship to the marker 39 onthe collar 36, the longitudinal displacement of the thimble 41 isindicated. For example, the indicator may be scaled to increments ofiongitudinal displacement of one-thousandths of an inch and even finerif desired. Accordingly, the selected stop teeth 9 may serve as a coarsepositioning and the thimble 41 as the vernier adjustment. It will benoted that the coarse adjustment may be set rapidly by merely slidingthe block 13 along the shaft and stopping at the position designated bya scale along the guide tracks 10.

I claim: 1. A machine tool stop comprising: a. a shaft; and b. stopmeans with a central opening for receiving said shaft and with a stopengaging surface, said stop means being movable axially along saidshaft, said stop means comprising a locking member movable betweenpositions of engagement and disengagement with said shaft, said stopmeans comprising rotatable actuating means rotatable about the axis ofsaid shaft for moving said locking member between the positions ofengagement and disengagement with said shaft.

2. A stop as claimed'in claim 1 wherein said stop means includes a blockwith a central opening for 3. A stop as claimed in claim 2 wherein saidstop means comprises an axially disposed pin disposed in engagement withsaid locking member for imparting movement thereto, said rotatableactuating means includes a central opening for receiving said shaft andis formed with a slot for receiving said pin, said slot of saidrotatable actuating means being formed to impart radial displacement tosaid pin, whereby rotation of said rotatable actuating means about theaxis of said shaft displaces said pin to impart movement to said lockingmember within the slot formed in said block for displacing said lockingmember radially relative to the axis of said shaft to move said lockingmember between the positions of engagement and disengagement with saidshaft.

4. A stop as claimed in claim 3 wherein said shaft is formed withaxially spaced projections therealong and wherein said locking memberselectively engages one or more of said projections for locking saidstop means to said shaft.

5. A stop as claimed in claim 4 wherein said shaft includes means forattachment to a machine tool.

6. A stop as claimed in claim 3 in which said shaft includes guide trackmeans parallel to the axis of said shaft, and said stop means includesgrooves for receiving in sliding guiding engagement said guide trackmeans for sliding said stop means axially along said shaft.

7. A stop as claimed in claim 4 wherein said projections are in the formof a plurality of axially spaced apart ratchet teeth and the lockingmember is in the form of a pawl, the teeth and the pawl being shaped forcomplementary locking engagement.

8. A stop as claimed in claim 3 wherein said stop means includes avernier adjustment for the fine adjustment of the position of the stopsurface along said shaft.

9. A stop as claimed in claim 8 in which said vernier adjustment is inthe form of a vernier thimble having a threaded inner surface.

l0. A stop as claimed in claim 7 wherein said shaft is formed with aplurality of parallel sets of axially spaced ratchet teeth and said stopmeans includes a plurality of angularly spaced pawls, said pawls beingarranged to engage said parallel sets of ratchet teeth respectively.

11. A stop as claimed in claim 10in which said shaft includes an axiallydisposed guide track between successive parallel sets of teeth, and saidstop means includes a groove between successive pawls, said groovesreceive said tracks respectively in sliding guided engagement forsliding said stop means axially along said shaft.

12. A stop as claimed in claim 10 wherein said stop means includes ablock with a centrally opening for receiving said shaft and with aplurality of radially disposed, angularly spaced slots, there being apawl disposed in each of said slots in said block for radial movementrelative to the axis of said shaft for movement twee sitio f en a ementand disen a ment 33m sai l iaft, s a lfstop m eans comprises a a xiallydisposed pin disposed in engagement with a pawl for imparting movementthereto, said stop means including a rotation actuating means with acentral opening for receiving said shaft and with a plurality of slotsfor receiving said pins respectively, whereby rotation of said rotatableactuation member about the axis of said shaft displaces said pins toimpart movement to said pawls within said slots of said block fordisplacing said pawls radially relative to the axis of said shaft tomove said pawls between the positions of engagement and disengagementwith said shaft.

1. A machine tool stop comprising: a. a shaft; and b. stop means with acentral opening for receiving said shaft and with a stop engagingsurface, said stop means being movable axially along said shaft, saidstop means comprising a locking member movable between positions ofengagement and disengagement with said shaft, said stop means comprisingrotatable actuating means rotatable about the axis of said shaft formoving said locking member between the positions of engagement anddisengagement with said shaft.
 2. A stop as claimed in claim 1 whereinsaid stop means includes a block with a central opening for receivingsaid shaft and with a radially disposed slot in which said lockingmember is disposed for radial movement relative to the axis of saidshaft for movement between positions of engagement and disengagementwith said shaft.
 3. A stop as claimed in claim 2 wherein said stop meanscomprises an axially disposed pin disposed in engagement with saidlocking member for imparting movement thereto, said rotatable actuatingmeans includes a central opening for receiving said shaft and is formedwith a slot for receiving said pin, said slot of said rotatableactuating means being formed to impart radial displacement to said pin,whereby rotation of said rotatable actuating means about the axis ofsaid shaft displaces said pin to impart movement to said locking memberwithin the slot formed in said block for displacing said locking memberradially relative to the axis of said shaft to move said locking memberbetween the positions of engagement and disengagement with said shaft.4. A stop as claimed in claim 3 wherein said shaft is formed withaxially spaced projections therealong and whereIn said locking memberselectively engages one or more of said projections for locking saidstop means to said shaft.
 5. A stop as claimed in claim 4 wherein saidshaft includes means for attachment to a machine tool.
 6. A stop asclaimed in claim 3 in which said shaft includes guide track meansparallel to the axis of said shaft, and said stop means includes groovesfor receiving in sliding guiding engagement said guide track means forsliding said stop means axially along said shaft.
 7. A stop as claimedin claim 4 wherein said projections are in the form of a plurality ofaxially spaced apart ratchet teeth and the locking member is in the formof a pawl, the teeth and the pawl being shaped for complementary lockingengagement.
 8. A stop as claimed in claim 3 wherein said stop meansincludes a vernier adjustment for the fine adjustment of the position ofthe stop surface along said shaft.
 9. A stop as claimed in claim 8 inwhich said vernier adjustment is in the form of a vernier thimble havinga threaded inner surface.
 10. A stop as claimed in claim 7 wherein saidshaft is formed with a plurality of parallel sets of axially spacedratchet teeth and said stop means includes a plurality of angularlyspaced pawls, said pawls being arranged to engage said parallel sets ofratchet teeth respectively.
 11. A stop as claimed in claim 10 in whichsaid shaft includes an axially disposed guide track between successiveparallel sets of teeth, and said stop means includes a groove betweensuccessive pawls, said grooves receive said tracks respectively insliding guided engagement for sliding said stop means axially along saidshaft.
 12. A stop as claimed in claim 10 wherein said stop meansincludes a block with a centrally opening for receiving said shaft andwith a plurality of radially disposed, angularly spaced slots, therebeing a pawl disposed in each of said slots in said block for radialmovement relative to the axis of said shaft for movement betweenpositions of engagement and disengagement with said shaft, said stopmeans comprises an axially disposed pin disposed in engagement with apawl for imparting movement thereto, said stop means including arotation actuating means with a central opening for receiving said shaftand with a plurality of slots for receiving said pins respectively,whereby rotation of said rotatable actuation member about the axis ofsaid shaft displaces said pins to impart movement to said pawls withinsaid slots of said block for displacing said pawls radially relative tothe axis of said shaft to move said pawls between the positions ofengagement and disengagement with said shaft.